This invention relates to fasteners and more particularly to thread locking type blind fasteners that can be installed into a narrow flat structural sheet member wherein provision is made to suitably anchor such fastener to permit torquing of the fastener once installed without encountering any spin of the fastener. Such blind fasteners are used where it is not possible to drill and tap the structural sheet member since it is a narrow flat connecting structural plate member of thin material.
Various designs of blind fasteners have been made which consist of a flat head and a threaded tubular body, which tubular body can be inserted through a hole in a structure and expanded to bear against the back or blind side of the structure and secure such fastener, after which the threaded portion can function as a stationary nut for fastening the desired external component thereto. In the present invention the structural plate member itself is a thin very narrow strip of material and cannot physically be tapped or threaded when viewed as a strip in a vertical direction. Generally in this kind of structure special structures are made and fastened first to the thin structural member as disposed in its vertical direction as by welding another member thereto and then these special structures provide the means by which a fastener is attached thereto. In the present invention the fastener alone can be attached to a vertically disposed narrow strip of material by cutting a small narrow longitudinally extending elongated hole into the plane of the material in contradistinction to a circular hole in a flat plate and thence secure the fastener to the narrow material by expanding a portion of the fastener for gripping the vertically disposed structural material. The head end of the fastener which has a thicker wall portion than the remainder of the fastener has slots cut into the head which are slidingly and frictionally received by the narrow strip of the structural material or sheet member which prevents rotation and acts as an anti-torque device to stabilize any movement. The upsetting process expands a small portion of the fastener into notches cut into the narrow elongated hole or slot in the narrow strip of material or the thin structural member which prevents pullout. Such fastener is simple in construction and inexpensive, providing for maximum strength against pulling out of the hole as well as against slippage or rotation.